package stackdemo;

import java.util.Stack;

class ValidBrackets {
    public boolean isValid(String s) {
        Stack<Character> stack = new Stack<>();
        for(int i = 0;i < s.length();i++) {
            char ch = s.charAt(i);
            if (ch == '(' || ch == '[' || ch == '{') {
                stack.push(ch);
            }else {
                if (stack.isEmpty()) {
                    return false;
                }
                char ch2 = stack.peek();
                if (ch == ')' && ch2 == '(' || ch == ']' && ch2 == '[' || ch == '}' && ch2 == '{') {
                    stack.pop();
                }else {
                    return false;
                }
            }
        }
        if (!stack.isEmpty()) {
            return false;
        }
        return true;
    }
}
